Continuous row of slide fastener links



Jan. 27, 1970 H. Pom-:PP

A CONTINUOUS Row oF SLIDE FASTENER LINKS v 3 Sheets-Sheet 1 Filed OCT.. 19. 1966 Jan. 27, 1970 lH. PQREPP CONTINUOUS ROW OF 'SLIDE FASTENER LINKS 3 Sheets-Sheet 2 Filed Oct. 19, 1966 mv l5 Fig. I4I

itorney" Jan. 27, 1970 H. pcm-P y CONTINUOUS Row 0F 'SLIDE FAs'rENE-R LINKS 3 Sheets-Sheet 3 Filed ocx. 19, l196e mvmron Hans Porepp swg@ "United States Patent O CONTINUOUS Row oF SLIDE FAs'rENER LINKS Hans Porepp, Am Rebberg, Wangen (Bodensee), Germany Filed Oct. 19, 1966, Ser. No. 587,926 Claims priority, applicatisopggrmany, Oct. 26, 1965, Int. c1. A44b 19/16 U.S. Cl. 2li-205.13 5 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a continuous, string of slidefastener coupling members made of a synthetic-resin filament or thread.

Continuous strings or chains of slide-fastener coupling members made of plastic material in helicoidal or meandering form, or a helical spring, are known; these strands are connected to a carrier ribbon or support tape by sewing or weaving, whereby a pair of such slide-fastener coupling-member strands with the respective carrier or support tape or band may be combined to form a slide fastener. Meander-like strings of slide-fastener link members may be made such that the filament of plastic material is provided along the center line of the meander with deformations ofthe meander apex serving as coupling surfaces, whereupon the meander is bent to form a U- shape about this longitudinal center line so that the legs of the U straddle the edge of a carrier ribbon, or a connecting strip respectively, while the coupling surfaces project freely beyond the ribbon edge. A slide-fastener half is thus provided with a row of coupling surfaces at the apex of the U-like bent meander.

Strings of slide-fastener coupling members are also known which comprises helically wound threads of plastic material provided with a row of coupling surfaces made by coining and extending along a longitudinal line wherein the profile of the helical spring may be oval or attened.

The coupling surfaces of the two aforementioned strings of slide-fastener link members made by coining are, due to the small diameters of the thread used, substantially merely flat thread enlargement which, upon pulling together a pair of such link memberstrings to form a slide fastener, are engageable with the free spaces behind the arcs or turns of the other link member string. It will be appreciated that security against opening of such slide fasteners is not fully satisfactory, since the individual convolutions or meander links tend to spread upon vbending or buckling of the slide fastener, whereby the coupling heads may be released.

Therefore the object of the invention is to prevent the danger of separation of meandering or helical-coil coupling elements of slide fasteners and, according to the invention this is achieved by providing the strands with coupling surfaces at staggered, opposed arc apexes, or winding apexes respectively, and bending the lmeander or the flattened helical spring to form a U about the longitudinal center line in such a way that two continuous, parallel strings of links members are formed as one half of a slide fastener.

Thus it is achieved that practically a continuous double string of slide fastener link members yis provided having Mice staggered coupling surfaces and heads so that in drawing together a pair of such slide-fastener coupling elements to form a slide fastener, a double coupling engagement is achieved; the coupling engagement cannot break-up normally to the plane of the slide fastener 4because the staggered coupling surfaces of the two slide-fastener halves support each other to the coupling plane when engaged, and if bending of the connection transversely of the coupling plane should occur the coupling surfaces of the one engagement row of the two slide-fastener halves will indeed spread a little but, as a compensation, the coupling surfaces of the other engagement row of the two slide-fastener halves are correspondingly urged against each other into closer engagement.

The strings of slide-fastener link members of different embodiments according to the invention and the method of producing the same as well as the device used therefore shall now be described in connection with the attached drawings.

In the drawings:

FIG. 1 is a top view of a meandering plastic thread prior to being bent into a U-shape according to the invention;

FIG. 2 is a transverse cross section of the meander of FIG. l;

FIG. 3 is a transverse cross section of the meander during the U-shaped bending;

FIG. 4 is a transverse cross section of the meander of the finished string of link members or coupling element;

FIG. 5 is a top view of the coupling surfaces of the finished string of link members shown in FIG. 4;

FIG. 6 is a top View of a device for laying a plastic thread or filament in the form of a meander;

FIG. 7 is a top view of a device modified with respect to FIG. 6;

FIG. 8 is a section along line VIII-VIII of FIG. 6;

FIG. 9 is a top view of a meandering thread of plastic material with a modified meandering shape with respect to that shown in FIGS. 1 and 5 FIG. 1() is a side view of the string of link members made of a meander according to FIG. 9;

FIG. 10a is a modified embodiment of the present invention;

FIG. 11 is a top view of the coupling surfaces of the string of link members shown in FIG. 10;

FIG. 12 is a cross section of the finished string of link members subsequent to the U-shaped bending of the meander shown in FIG. 10;

FIG. 13 is a top view of another meandering element according to -another embodiment of the invention;

FIG. 14 is a side view of a string of link members made of a meander as shown in FIG. 13, partly in engagement with a second string of link members;

FIG. 15 is a top view of coupling surfaces according to the embodiment shown in FIG. 14; and

FIG. 16 is a Schematic illustration of a machine for the production of strings of link members according to the FIGS. l to l5.

The string of link members for slide fasteners according to FIGS. l to 5 is made of a plastic synthetic resin thread or filament 1 of preferably round cross-sectional shape. The plastic thread 1 is initially laid in zig-zag fashion in form of a meander according to FIG. 1, in which the meander is provided with coupling surfaces or heads 4 at the alternatingly opposite return bends or loops 2, as will be explained in detail hereinafter, thus providing the transverse cross-sectional profile according to FIG. 2 if laid in this manner; the meander has a cross sectional shape of a recumbent figure eight wherein the coupling heads or surfaces 4a are formed by thread widenings or enlargement in the longitudinal direction of the meander. This meander is then bent to a U-shape about the longitudinal center line or bent axis 3 either continuously or stepwise, as shown in FIGS. 3 and 4, so that the loops are connected by bights having the common bend axis 3 and practically two rows of coupling surfaces or heads are formed; the coupling surfaces 4a on opposite sides of the median plane 3 are staggered relative to each other (see FIGS. 4 and 5). When bending the meander about its longitudinal center 3 to the U-shape a securing string 5, or the like, may be inserted as shown in FIGS. 3 and 4.

It is also possible, according to the invention to start out from a helically wound plastic material provided with coupling surfaces at the staggeredly opposed winding apexes whereupon it is attened, and then the flattened helical spring now having a meandering conguration is bent to a U-shape about the longitudinal center line, whereby also a string of link members witha double row of coupling surfaces is formed having their coupling surfaces arranged in staggered relation.

It will be appreciated that due to the U-shaped bending of the meander and the U-shaped bending of the attened helical spring a double coupling engagement is provided, thereby offering a great safety against the danger of breaking open; breaking open normally (Le. transversely) to the coupling plane of two coupled strings of link members is avoided by the fact that the coupling surfaces in alternatingly staggered relationship on opposite sides of the median plane parallel to the coupling rows support each other normally to the coupling plane.

The manufacture of the meander according to FIGS. l and 2 may, for instance, be achieved by means of a device according to FIG. 6 consisting of a base 11 including two rows of teeth 6 and 7 arranged in parallel relation having teeth arranged in staggered relation in this embodiment. In this case the plastic thread is fed by a corresponding thread guide through two gaps of the teeth staggered with respect to each other, and then the thread is provided with a coupling surface 4a at the outer side of, for instance, the row of teeth 6 by a coining ram operating against the base 11.

These coupling surfaces are formed as a widening of the thread, the width of which is greater than that of the teeth gaps. Then the thread 1 is returned in opposite direction through the same gap of the row of teeth 6 and through the thread guide and guided through the staggered gap of the row of teeth 7 and here the thread is returned in opposite direction through the same gap of the teeth as described above. By this type of production the coupling surfaces 4a prevent the pulling of the thread through the gaps of the teeth when running back and forth, and the reciprocating legs of the meander are alternately disposed in superposed positions, whereby a meander with a cross sectional shape of a recumbent figure eight, corresponding to FIG. 2 is formed; the figureeight member is then bent to a U-shape according to FIG. 4 as already mentioned. The heads on alternate sides of the median plane have bend centers lying along lines parallel to the bend axis or median plane (FIG. 4). The laying of the meander with the aid of the device shown in FIG. 6 is illustrated in cross section in FIG. 8, wherein it is also shown that the coupling surfaces are made by exerting a coining pressure in the direction of the arrow 10.

Evidently, it is also possible to arrange the teeth 8 of the two rows of teeth 6 and 7 opposite to each other on the base 11 and then to guide the plastic thread in the manner shown in FIG. 7. Here for the sake of clearer illustration the coupling surfaces are pulled apart exaggeratedly and, of course, care must be taken that the coupling surfaces 4b of the two rows of coupling surfaces are not spaced from each other too much since it is desired that the two rows of link members to be engaged support each other normally (transversely) to the coupling plane.

The embodiment shown in FIG. 7 may, however, be used in such a way that the free distances between the return bends on both sides of the meander correspond substantially to three times the diameter of thread. Now, if the meander is bent to a U shape about the center line 3 in such a manner that the coupling surfaces of both legs lie on one line, a row of slide-fastener links with an aligned row of coupling surfaces is obtained, whereby in this case, when two such rows of links are used as fastener halves a simple coupling engagement of these halves is provided and the production of these rows of fastener links is speeded up.

It will be appreciated that it is also possible to use the device according to FIG. 6 or 7 to lay a meander in one plane, as shown in FIG. 9 and to provide the plastic thread upon each passage through the two rows of teeth 6 and 7 with coupling surfaces 4b at the outer sides. 'Ihis meander is again bent about the longitudinal center line 3 to a U-shape corresponding to FIGS. l0 to 12, whereby a row of slide fastener links with two rows of coupling surfaces is formed. In this embodiment, however, a fastener string 5 must in each case tbe placed between the legs of the meander to be bent into a U-shape in order to allow the coupling element to be secured to a carrier ribbon by sewing in the well-known manner. In this case the coupling surfaces-may also be provided with any other contour; for example, the return bends 2 may be deformed to a head, and the sides of the heads may project on either sidein longitudinal direction. Such an embodiment is shown in FIG. 10a in which the plastic thread 1 at the outer sides ofthe rows of teeth 6 and 7 is provided on one side with` angular indentations and on the other side with an arcuate recess by coining, whereby head-like coupling surfaces 4 are formed when the thread after each passage is laid around a tooth of the rows 6 and 7. It is also possible to coin differently shaped coupling surfaces, such as those shown in FIGS. 13 to 15, according to which the return bends of the meander are provided with impressions 4a and 4d on opposite sides in relation to the meander plane, wherein, of course, the base 11 must be provided with corresponding projections for forming the impressions 4d while ythe coining 4c is formed by va ram working against the base 11. In this case also the meander is bent to a U-shape about the longitudinal center line 3 and a fastener string (not shown) is placed between the legs of the meander so that again a row of fastener links with two rows of coupling surfaces is formed, representing the one half of a slide fastener.

The coupling surfaces 4b according to the examples shown in FIGS. 9, l0, 1l and 12 may by the way also be produced in such a manner that a coining ram operates against the outer sides of the teeth 8 of the two rows of teeth 6 and 7 whereby widenings of the thread are formed disposed substantially normally to the plane of the meander, as shown in FIG. 9. In this the coupling engagement of two finished rows of fastener links takes place in lateral direction, i.e. perpendicularly to the closure plane, While the coupling engagement in the embodiment according to'FIGS. 1 to 5 takes place in longitudinal direction of the rows of fastener links.

In order to provide a continuous production of the meander-like laid plastic threads to form rows of fastener links, the base 11 Iof the device according to FIGS. 6 and 7 is practically formed as a drum with two rows of teeth 6 and 7 extending in parallel relation around the circumference. This drum with its two rows of teeth is periodically indexed after each reciprocating passage of the thread through a gap between the teeth of rows 6 and 7, while the thread guide always operates reciprocatingly in the same zone.

According to FIG. 16 two drums, each provided with .two parallel rows of circumferentially extending teeth, may be journalled in a frame in one plane rotatably about parallel axes in such a manner that the two gears 13 and 14 nearly contact each other in one point. Below the two gears 13 and 14 and symmetrically thereto a slide 15 is guidedly supported to reciprocate in parallel relation to the two gear shafts and this slide 15 is provided with two thread guides 15a and 15b guiding the plastic threads 1a and 1b in reciprocating manner through the two gaps of the teeth as described in connection with FIGS. 6 and 8, or that according to FIG. 9 respectively, and simultaneously the coupling surfaces are coined on the outer sides of the rows of teeth 6 and 7. The two thus produced meanders are taken along by the rows of teeth 13 and 14 when they are indexed periodically, whereupon the U-shaped bending of the meander takes place on the gears 13 and 14 in such a manner that a disc 16 operates between the rows of teeth 6 and 7 against the longitudinal center line of each meander and somewhat weakens the thread at this zone. Then the meander with its coupling surfaces is lifted from the circumference of the gears 13 and 14 by a guide 17 and is bent to a U- shape while a string 19 may be guided at 20 Ibetween the legs of the U-shaped meander. Subsequent to the U-shaped bending the row of fastener links is stabilized regarding its shape by heating means 18 and nally the two rows of fastener links merge at 21 at the contacting point of the two gears 13 and 14 and are lifted out of the gears by ywedges and thereby brought into engagement and move through a channel so that then the sewing of the two engaged rows of fastener links on a carrier ribbon by means of a suitable sewing machine may take place.

What I claim is:

1V. A coupling element for attachment to a support tape in the formation of a slide-fastener stringer, said coupling element comprising a continuous synthetic-resin thread in meandering configuration with respective rows of coupling heads on opposite sides of a longitudinal median plane, the heads of the rows being longitudinally staggered alternatingly on opposite sides of said plane and formed as arcuate loops having centers of curvature lying along respective lines Iparallel to one another and to said plane, the loops of successive heads on alternate sides on said plane being interconnected by arcuate bights having a common bend axis lying in said plane parallel to said lines, said heads being provided with formations extending transversely of the thread of each loop.

2. A coupling element as defined in claim 1 wherein the successive loops in staggered opposed relationship have legs alternately disposed in parallel superposed positions adjacent said formations, and the meandering configuration has the cross-sectional shape of a figure 8 bent into a U about an axis parallel to the intersections of the legs.

3. A coupling element as deiined in claim 1, further comprising a longitudinally extending cord for securing said element'to said tape disposed in said bights along said axis.

4. A coupling element as delined in claim 1 wherein said formations extend transversely to the longitudinal direction of the coupling element.

5. A coupling element as defined in claim 1 wherein said formations extend in the longitudinal direction of the coupling element.

References Cited UNITED STATES PATENTS 3,015,868 1/1962 Ruhrmann. 3,149,387 9/1964 Ruhrmann.

FOREIGN PATENTS 575,938 4/1958 Italy.

BERNARD A. GELAK, Primary Examiner U.S. Cl. X.R. 2LP-205.16 

